The present invention relates generally to refrigeration compressors and more specifically to hermetic refrigeration compressors incorporating a motor cover assembly which is designed to enable the air gap between the motor rotor and stator to be accurately set prior to securing the cover thereto and a method of assembling such motor covers and stators.
Hermetic refrigeration compressors normally incorporate a compressor and associated driving motor within a hermetically sealed shell. The motor will generally include a rotor secured to a drive shaft journaled in the compressor housing or other suitable bearing means and a stator secured to the compressor housing by means of bolts extending through the stator core. In many designs a motor cover is also provided which is secured to one end of the stator by the same bolts used to secure the stator to the compressor housing. In such designs it is very difficult to insure accurate setting of the air gap between the rotor and stator due to the presence of the motor cover.
However, the present invention provides an improved motor/motor cover assembly of the aforementioned general design but which allows the stator to be accurately positioned and secured to the compressor prior to assembly of the motor cover while still allowing the stator securing bolts to be used to secure the motor cover to the stator. In the present design a first pair of stator securing bolts are used to secure the stator in position once the air gap has been set. Thereafter the cover member is positioned over the stator and a second pair of stator securing bolts are inserted therethrough and tightened to thereby secure both the stator to the compressor housing and the cover to the stator.
This arrangement thus greatly facilitates the accurate and precise setting of the air gap yet does not require the separate fabrication and assembly of any additional components. Thus cost savings are obtained both in terms of labor and material while also providing a positive reliable securement of the motor cover.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.